镇巴县地质灾害发育规律与危险性评价

以"汉江中游任河流域镇巴县幅地质灾害调查及专题研究"项目为依托,基于区域地质环境概况、遥感解译与野外实地考察,研究了镇巴县幅地质灾害的发育规律。在此基础上,选择坡高、坡度、坡形、降雨量、工程地质岩组、距断层距离、距河流距离、人类工程活动与灾害点密度9种评价因子,采用层次分析法建立各评价因子的判断矩阵,确定地质灾害危险性评价指数,对镇巴县幅地质灾害危险性进行评价和分区。结果表明：（1）镇巴县幅地质灾害类型主要为滑坡、崩塌、泥石流,其中滑坡93处,崩塌6处,泥石流4处;（2）地质灾害多发育在坡形为凹凸面坡、坡度为0°~10°、起伏度为0~30 m的斜坡中,且集中分布在河谷两侧的高程为500~800 m的低山区;（3）地质灾害危险性可分为高、中、低三类,面积分别为62.05、143.43、224.57 km²。高危险区主要分布在泾洋河流域,占总面积的14.4%。

Development Regularity and Risk Assessment of Geohazards in Zhenba County

Based on the project of "Geological Hazard Investigation and Special Research of Zhenba County in the Middle River of Hanjiang River", and combined with regional geological environment overview, remote sensing interpretation and fieldwork, the development regularity of geological hazards in Zhenba County were studied. According to the results, there are nine conditioning evaluation factors: slope height, slope, slope shape, rainfall, engineering geological rock group, distance from fault, distance from river, human engineering activity and disaster point density, which were extracted. Then the judgment matrix of conditioning factors and factor classes were conducted by analytic hierarchy process method,and geological hazard index was built. Finally the geological hazard of Zhenba County was assessed and the risk of geological hazard map was classified. The results are as follows: (1) the main types of geological disasters in Zhenba County are landslides, collapses, and debris flows, including 93 landslides, 6 collapses, and 4 debris flows;(2) Geological disasters are mostly developed in concave-convex slopes, slopes with angles of 0°~10°, slopes with undulations of 0~30 m, and are concentrated in low mountains with elevations of 500~800 m on both sides of the valley;(3) The risk of geological hazard map can be classified into three classes, including high, moderate, and low, with an area of 62.05 km², 143.43 km² and 224.57 km² respectively. High-risk areas are mainly distributed in the Jingyang River Basin, accounting for 14.4% of the total area.